Well, from the looks of it, you aren't giving us much to work with. Try to explain what you mean by "maxing out" and how you would do so, and also to what power would you want to bring the diode.
From what i can tell though, and trust me when i say i'm NOT an expert, you seem to have found a weak <5mW diode. I would highly advise against trying to increase the output of it, since the probably cheap design of it probably will not withstand any power greater than 10mW (double the original)
At any rate, you should wait for a more experienced user to roll into the scene if you want a clearer answer, although threads like this one probably already exist, so it might be useful to go looking for them while awaiting your knight-user in shining rep.